Multilayer ceramic capacitor

ABSTRACT

A multilayer ceramic capacitor includes a ceramic body including first and second surfaces opposing each other, and third and fourth surfaces connecting the first and second surfaces, a plurality of internal electrodes disposed inside the ceramic body, exposed from the first and second surfaces, and having an end exposed from the third surface or the fourth surface, and a first side margin and a second side margin respectively disposed on the first and second surfaces, from which end portions of the plurality of internal electrodes are exposed. The first and second side margins include a base material powder of a barium titanate-based base powder and a subcomponent. The subcomponent includes terbium (Tb) as a first subcomponent including a lanthanide rare earth element, and a content ratio of the terbium (Tb) to a content of the first subcomponent (RE) excluding the terbium (Tb) satisfies 0.110≤Tb/RE≤2.333.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims benefit of priority to Korean Patent ApplicationNo. 10-2019-0142465 filed on Nov. 8, 2019 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a multilayer ceramic capacitor and amethod of manufacturing the same, and more particularly, to a multilayerceramic capacitor in which mechanical strength may be improved and hightemperature and moisture resistance may be improved, and a method ofmanufacturing the same.

BACKGROUND

In general, electronic components using a ceramic material, such ascapacitors, inductors, piezoelectric elements, varistors, orthermistors, include a ceramic body formed of a ceramic material, aninternal electrode formed inside the body, and an external electrodeinstalled on the surface of the ceramic body to be connected to theinternal electrode.

Recently, as electronic products have become miniaturized andmultifunctional, chip components are also miniaturized and highlyfunctionalized, and thus, high capacity products, for example,multilayer ceramic capacitors having small sizes and high capacities,are required.

For miniaturization and high capacitance of multilayer ceramiccapacitors, it is necessary to secure a dielectric material having gooddielectric properties and excellent withstand voltage characteristics.

In addition, thinning of a dielectric and a significant increase in anelectrode effective area (increasing the effective volume fractionrequired for capacity implementation) are required.

However, a local reduction in dielectric thickness may occur due to thethinning of the dielectric and the marginal step difference, and thus, astructural design change to significantly reduce a withstand voltagedrop phenomenon occurring due to such a local reduction is essential.

To implement a small-sized and high capacity multilayer ceramiccapacitor as described above and to prevent a withstand voltage dropphenomenon, in manufacturing a multilayer ceramic capacitor, there is amethod in which the internal electrode is exposed in the width directionof the body, thereby significantly increasing the internal electrodearea in the width direction through a marginless design, and a separatemargin portion is attached to the electrode exposed surface of the chipin the width direction, in the operation before firing after chipfabrication as above.

However, when the multilayer ceramic capacitor is manufactured asdescribed above, the dielectric composition of the ceramic body is usedas is without differentiating the dielectric composition of the sidemargin from the dielectric composition of the ceramic body.

Therefore, there is a problem in which the interface gap between theelectrode end portion and the margin portion join surface is not filled,the interface gap being inevitably generated due to the problem oflowering the densification of the side margin and the sintering drivemismatching phenomenon of the dielectric of the side margin and theinternal electrode during the sintering process.

In addition, since in the related art, a ceramic dielectric sheet thatacts as a margin is attached to a green chip cut without a margin, byphysical compression, and then a sintered body having a rigid body isformed through a high temperature heat treatment. Thus, in this case,when the adhesive force between the electrode exposed surface and thesheet for forming a margin portion in the operation before sintering isinsufficient, poor appearance due to removal of margin and seriousdefects leading to interfacial cracks may occur.

In addition, voids are generated between the electrode end and themargin interface when the volume change occurs inside the chip due toshrinkage of the internal electrode during high temperature heattreatment, acting as a starting point of crack generation or as amoisture penetration path, thereby causing a decrease in moistureresistance reliability.

In addition, to solve the above problems, when the material with highsintering driving force is applied as a general method, the aggregationof an outermost internal electrode near the interface due to excessivegrain growth is intensified, resulting in increasing a drop in withstandvoltage due to the electrode and dielectric layer unevenness.

Therefore, the dielectric of the margin region should have an excellentsintering driving force, so that the same sintered-body density as thatof the ceramic body may be ensured, even with a low physical fillingdensity, thereby significantly reducing the decrease in the strength ofthe multilayer ceramic capacitor.

In addition, the dielectric used in the margin region should be able tomore actively move the material at a high temperature to fill theinterface void.

In addition, the interface bonding force should be improved by formingan oxide layer on the end joining surface by reaction with the internalelectrode.

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

An aspect of the present disclosure is to provide a high capacitymultilayer ceramic capacitor in which mechanical strength and hightemperature and moisture resistance may be improved, and a method ofmanufacturing the same.

According to an aspect of the present disclosure, a multilayer ceramiccapacitor includes a ceramic body including first and second surfacesopposing each other, and third and fourth surfaces connecting the firstand second surfaces, a plurality of internal electrodes disposed insidethe ceramic body, exposed from the first and second surfaces, and havingan end exposed from the third surface or the fourth surface, and a firstside margin and a second side margin respectively disposed on the firstand second surfaces, from which end portions of the plurality ofinternal electrodes are exposed. The first and second side marginsinclude a base material powder of a barium titanate-based base powderand a subcomponent. The subcomponent includes terbium (Tb) as a firstsubcomponent including a lanthanide rare earth element, and a contentratio of the terbium (Tb) to a content of the first subcomponent (RE)excluding the terbium (Tb) satisfies 0.110≤Tb/RE≤2.333.

According to an aspect of the present disclosure, a multilayer ceramiccapacitor includes a ceramic body including first and second surfacesopposing each other, and third and fourth surfaces connecting the firstand second surfaces, a plurality of internal electrodes disposed insidethe ceramic body, exposed from the first and second surfaces, and havingan end exposed from the third surface or the fourth surface, and a firstside margin and a second side margin respectively disposed on the firstand second surfaces, from which end portions of the plurality ofinternal electrodes are exposed. The first and second side marginsinclude a base material powder of a barium titanate-based base powderand a subcomponent. The subcomponent includes terbium (Tb) as a firstsubcomponent including a lanthanide rare earth element. A content ratioof the terbium (Tb) to a content of the first subcomponent (RE)excluding the terbium (Tb) satisfies 0.110≤Tb/RE≤2.333. A dielectriccomposition included in the first and second side margins and adielectric composition included in the ceramic body are different fromeach other, and a content of the terbium (Tb) included in the first andsecond side margins is more than a content of terbium (Tb) included inthe ceramic body. A content ratio of the terbium (Tb) included in thefirst and second side margins to a content of the base material powderincluded in the first and second side margins, is greater than a contentratio of terbium (Tb) included in the ceramic body to a content of abarium titanate-based base powder included in the ceramic body

According to an aspect of the present disclosure, a multilayer ceramiccapacitor includes a ceramic body including first and second surfacesopposing each other, and third and fourth surfaces connecting the firstand second surfaces, a plurality of internal electrodes disposed insidethe ceramic body, exposed from the first and second surfaces, and eachhaving an end exposed from the third surface or the fourth surface, anda first side margin and a second side margin respectively disposed onthe first and second surfaces, from which end portions of the pluralityof internal electrodes are exposed. The first and second side marginsinclude a base material powder of a barium titanate-based base powderand a subcomponent. The subcomponent includes terbium (Tb) and one ormore other lanthanide rare earth elements as a first subcomponent. Acontent ratio of the terbium (Tb) included in the first and second sidemargins to a content of the base material powder included in the firstand second side margins, is greater than a content ratio of terbium (Tb)included in the ceramic body to a content of a barium titanate-basedbase powder included in the ceramic body. A content of the terbium (Tb)satisfies 0.15 mol≤Tb≤1.35 mol with respect to 100 mol of the basematerial powder included in the first and second side margins.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic perspective view illustrating a multilayer ceramiccapacitor according to an embodiment;

FIG. 2 is a cross-sectional view taken along line I-I′ of FIG. 1;

FIG. 3 is a cross-sectional view taken along line II-II′ of FIG. 1;

FIG. 4 is a top plan view illustrating one dielectric layer constitutingthe multilayer ceramic capacitor illustrated in FIG. 1; and

FIGS. 5A to 5F are cross-sectional views and perspective viewsschematically illustrating a method of manufacturing a multilayerceramic capacitor according to another embodiment.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent to one of ordinary skill inthe art. The sequences of operations described herein are merelyexamples, and are not limited to those set forth herein, but may bechanged as will be apparent to one of ordinary skill in the art, withthe exception of operations necessarily occurring in a certain order.Also, descriptions of functions and constructions that would be wellknown to one of ordinary skill in the art may be omitted for increasedclarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the disclosure to one of ordinary skill in the art.

Herein, it is noted that use of the term “may” with respect to anexample or embodiment, e.g., as to what an example or embodiment mayinclude or implement, means that at least one example or embodimentexists in which such a feature is included or implemented while allexamples and embodiments are not limited thereto.

Throughout the specification, when an element, such as a layer, region,or substrate, is described as being “on,” “connected to,” or “coupledto” another element, it may be directly “on,” “connected to,” or“coupled to” the other element, or there may be one or more otherelements intervening therebetween. In contrast, when an element isdescribed as being “directly on,” “directly connected to,” or “directlycoupled to” another element, there may be no other elements interveningtherebetween.

As used herein, the term “and/or” includes any one and any combinationof any two or more of the associated listed items.

Although terms such as “first,” “second,” and “third” may be used hereinto describe various members, components, regions, layers, or sections,these members, components, regions, layers, or sections are not to belimited by these terms. Rather, these terms are only used to distinguishone member, component, region, layer, or section from another member,component, region, layer, or section. Thus, a first member, component,region, layer, or section referred to in examples described herein mayalso be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Spatially relative terms such as “above,” “upper,” “below,” and “lower”may be used herein for ease of description to describe one element'srelationship to another element as illustrated in the figures. Suchspatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, an element described as being “above” or “upper”relative to another element will then be “below” or “lower” relative tothe other element. Thus, the term “above” encompasses both the above andbelow orientations depending on the spatial orientation of the device.The device may also be oriented in other ways (for example, rotated 90degrees or at other orientations), and the spatially relative terms usedherein are to be interpreted accordingly.

The terminology used herein is for describing various examples only, andis not to be used to limit the disclosure. The articles “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The terms “comprises,” “includes,”and “has” specify the presence of stated features, numbers, operations,members, elements, and/or combinations thereof, but do not preclude thepresence or addition of one or more other features, numbers, operations,members, elements, and/or combinations thereof.

Due to manufacturing techniques and/or tolerances, variations of theshapes illustrated in the drawings may occur. Thus, the examplesdescribed herein are not limited to the specific shapes illustrated inthe drawings, but include changes in shape that occur duringmanufacturing.

The features of the examples described herein may be combined in variousways as will be apparent after an understanding of the disclosure ofthis application. Further, although the examples described herein have avariety of configurations, other configurations are possible as will beapparent after an understanding of the disclosure of this application.

The drawings may not be to scale, and the relative size, proportions,and depiction of elements in the drawings may be exaggerated forclarity, illustration, and convenience.

Subsequently, examples are described in further detail with reference tothe accompanying drawings.

FIG. 1 is a schematic perspective view illustrating a multilayer ceramiccapacitor according to an embodiment.

FIG. 2 is a cross-sectional view taken along line I-I′ of FIG. 1.

FIG. 3 is a cross-sectional view taken along line II-II′ of FIG. 1.

FIG. 4 is a top plan view illustrating one dielectric layer constitutingthe multilayer ceramic capacitor illustrated in FIG. 1.

FIGS. 5A to 5F are cross-sectional views and perspective viewsschematically illustrating a method of manufacturing a multilayerceramic capacitor according to another embodiment.

Referring to FIGS. 1 to 4, a multilayer ceramic capacitor according toan embodiment includes a ceramic body 110, a plurality of internalelectrodes 121 and 122 formed in the ceramic body 110, and externalelectrodes 131 and 132 formed on external surfaces of the ceramic body110.

The ceramic body 110 has a first surface 1 and a second surface 2opposing each other, and a third surface 3 and a fourth surface 4connecting the first and second surfaces to each other, and a fifthsurface 5 and a sixth surface 6, which are an upper surface and a lowersurface.

The first surface 1 and the second surface 2 may be defined as surfacesopposing each other in the width direction (W direction) of the ceramicbody 110, while the third surface 3 and the fourth surface 4 may bedefined as surfaces opposing each other in the length direction (Xdirection). The fifth surface 5 and the sixth surface 6 may be definedas surfaces opposing in the thickness direction (Z direction).

The shape of the ceramic body 110 is not particularly limited, but maybe a rectangular parallelepiped shape as illustrated in the drawings.

Ends of the plurality of internal electrodes 121 and 122 formed in theceramic body 110 are exposed to the third surface 3 or the fourthsurface 4 of the ceramic body.

The internal electrodes (121 and 122) may be provided as a pair of firstinternal electrode 121 and second internal electrode 122 havingdifferent polarities.

One end of the first internal electrode 121 may be exposed to the thirdsurface 3, and one end of the second internal electrode 122 may beexposed to the fourth surface 4.

The other ends of the first internal electrode 121 and the secondinternal electrode 122 are formed at a predetermined distance from thethird surface 3 or the fourth surface 4, which will be described in moredetail later.

First and second external electrodes 131 and 132 may be formed on thethird surface 3 and the fourth surface 4 of the ceramic body to beelectrically connected to the internal electrodes.

The multilayer ceramic capacitor according to an embodiment includes theplurality of internal electrodes 121 and 122 disposed inside the ceramicbody 110, exposed to the first and second surfaces 1 and 2 and havingone end to the third surface 3 or the fourth surface, and a first sidemargin 113 and a second side margin 114 disposed on the end portions ofthe internal electrodes 121 and 122 exposed to the first surface 1 andthe second surface 2.

The plurality of internal electrodes 121 and 122 are formed in theceramic body 110, and respective ends of the plurality of internalelectrodes 121 and 122 are exposed to the first surface 1 and the secondsurface 2, which are the surfaces of the ceramic body 110 in the widthdirection. The first side margin 113 and the second side margin 114 aredisposed on the exposed end portions, respectively.

A thickness d1 of the first side margin 113 and a thickness d1 of thesecond side margin 114 may be 18 μm or less.

According to an embodiment, the ceramic body 110 may be comprised of alaminate 111 in which a plurality of dielectric layers 112 arelaminated, and the first side margin portion 113 and the second sidemargin 114 formed on both sides of the laminate.

The plurality of dielectric layers 112 constituting the laminate 111 arein a sintered state and may be integrated so that boundaries betweenadjacent dielectric layers cannot be identified.

The length of the laminate 111 corresponds to the length of the ceramicbody 110, the length of the ceramic body 110 corresponds to the distancefrom the third surface 3 to the fourth surface 4 of the ceramic body110. For example, the third and fourth surfaces 3 and 5 of the ceramicbody 110 may be understood as the third and fourth surfaces of thelaminate 111.

The laminate 111 is formed by stacking the plurality of dielectriclayers 112, and the length of the dielectric layer 112 forms a distancebetween the third surface 3 and the fourth surface 4 of the ceramicbody.

Although not particularly limited, according to an embodiment, thelength of the ceramic body may be 400 to 1400 μm. In more detail, thelength of the ceramic body may be 400 to 800 μm or 600 to 1400 μm.

The internal electrodes 121 and 122 may be formed on the dielectriclayers, and the internal electrodes 121 and 122 may be formed in theceramic body 110 with one dielectric layer 112 interposed therebetweenby sintering.

Referring to FIG. 4, the first internal electrode 121 is formed on thedielectric layer 112. The first internal electrode 121 is not entirelyformed in the length direction of the dielectric layer. For example, oneend of the first internal electrode 121 may be formed at a predetermineddistance d2 from the fourth surface 4 of the ceramic body 110, and theother end of the first internal electrode 121 may be formed on the thirdsurface 3, to be exposed to the third surface 3.

The other end of the first internal electrode exposed to the thirdsurface 3 of the laminate is connected to the first external electrode131.

In contrast to the first internal electrode, one end of the secondinternal electrode 122 is formed at a predetermined distance from thethird surface 3, and the other end of the second internal electrode 122is exposed to the fourth surface 4 to be connected to the secondexternal electrode 132.

The dielectric layer 112 may have the same width as that of the firstinternal electrode 121. For example, the first internal electrode 121may be formed as a whole in the width direction of the dielectric layer112.

Although not particularly limited, according to an embodiment, the widthof the dielectric layer and the width of the internal electrode may be100 to 900 μm. In more detail, the width of the dielectric layer and thewidth of the internal electrode may be 100 to 500 μm or 100 to 900 μm.

As the ceramic body becomes smaller, the thickness of the side marginmay affect the electrical characteristics of the multilayer ceramiccapacitor. According to an embodiment, the side margin may have athickness of 18 μm or less, thereby improving characteristics of theminiaturized multilayer ceramic capacitor.

In an embodiment, the internal electrode and the dielectric layer areformed by being cut at the same time, and the width of the internalelectrode and the width of the dielectric layer may be the same as eachother. More details with regard thereto will be described later.

In this embodiment, the width of the dielectric layer is formed to bethe same as that of the internal electrode, and thus the ends of theinternal electrodes 121 and 122 may be exposed to the first and secondsurfaces of the ceramic body 110 in the width direction.

The first side margin 113 and the second side margin 114 may be formedon both side surfaces of the ceramic body 110 in the width direction, towhich the ends of the internal electrodes 121 and 122 are exposed.

The thickness of the first side margin 113 and the second side margin114 may be 18 μm or less. As the thickness of the first side margin 113and the second side margin 114 is smaller, the overlapping area of theinternal electrodes formed in the ceramic body may be further increased.

The thickness of the first side margin 113 and the second side margin114 is not particularly limited as long as it has a thickness that mayprevent the short of the internal electrode exposed to the side of thelaminate 111. For example, the thicknesses of the first side margin 113and the second side margin 114 may be 2 μm or more.

If the thickness of each of the first and second side margins is lessthan 2 μm, the mechanical strength against external impact may belowered. If the thickness of each of the first and second side marginsis more than 18 μm, the overlapping area of the internal electrodes maybe relatively reduced, and thus, it may be difficult to secure the highcapacity of the multilayer ceramic capacitor.

To significantly increase the capacity of the multilayer ceramiccapacitor, a method of thinning the dielectric layer, a method of highlamination of the thinned dielectric layers, a method of improving thecoverage of the internal electrode, and the like have been considered.

In addition, a method of improving the overlap area of the internalelectrodes forming the capacitance has been considered.

To increase the overlapping area of the internal electrodes, the marginarea in which the internal electrodes are not formed should besignificantly reduced.

In detail, as the multilayer ceramic capacitor becomes smaller, themargin area should be significantly reduced to increase the overlappingarea of the internal electrodes.

According to this embodiment, the internal electrode is formed entirelyin the width direction of the dielectric layer, and the thickness of theside margin is set to 18 μm or less, so that the overlapping area of theinternal electrodes is relatively wide.

In general, the more the dielectric layers are highly laminated, thethinner the thickness of the dielectric layer and the internalelectrode. Therefore, a phenomenon in which the internal electrode isshorted may occur more frequently. In addition, when the internalelectrode is formed only on a portion of the dielectric layer, a stepdifference may occur due to the internal electrode, thereby increasingaccelerated lifespan of the insulation resistance.

However, according to this embodiment, even when the internal electrodeand the dielectric layer of the thin film are formed, since the internalelectrode is formed entirely in the width direction of the dielectriclayer, the overlapping area of the internal electrodes may be increasedto increase the capacity of the multilayer ceramic capacitor.

In addition, a multilayer ceramic capacitor may have excellentcapacitance characteristics and excellent reliability by reducing thestep difference caused by the internal electrodes, to reduce acceleratedlifespan of the insulation resistance.

On the other hand, in manufacturing a multilayer ceramic capacitor, inthe related art, the dielectric composition of the ceramic body is usedwithout differentiating the dielectric composition for forming the sidemargins from the dielectric composition of the ceramic body.

Thus, in this case, the physical packing density of the dielectric inthe side margin is relatively low, thereby causing a problem in whichthe densification of the side margin is reduced, and due to themismatching phenomenon of the sintering drive between the internalelectrode and the dielectric of the side margin during the sinteringprocess, there arises a problem in which the interface gap between theelectrode end portion and the margin junction surface, inevitablygenerated, may not be filled.

In addition, the ceramic dielectric sheet serving as the side margin isattached to the green chip cut without the margin portion by physicalcompression, and then, the sintered body having a rigid body is formedthrough high temperature heat treatment. Thus, in a case in which theadhesive force between the electrode exposed surface and the sheet forforming margins in operation before sintering is insufficient, poorappearance due to side margin removal and serious defects leading tointerfacial cracks may occur.

In addition, voids are generated between the electrode end and themargin interface when the volume change occurs inside the chip due toshrinkage of the internal electrode during high temperature heattreatment, acting as a starting point of crack generation or as amoisture penetration path, thereby causing a decrease in moistureresistance reliability.

Therefore, the dielectric of the margin region should have an excellentsintering driving force, so that the same sintered-body density as thatof the ceramic body may be ensured, even with a low physical fillingdensity, thereby significantly reducing the decrease in the strength ofthe multilayer ceramic capacitor.

In addition, the dielectric used in the margin region should be able tomore actively move the material at a high temperature to fill theinterface void.

In addition, the interface bonding force should be improved by formingan oxide layer on the end joining surface by reaction with the internalelectrode.

According to an embodiment of the present disclosure, the dielectriccomposition included in the first and second side margins 113 and 114and the dielectric composition included in the ceramic body 110 aredifferent from each other.

The first and second side margins 113 and 114 include a barium titanatebase material powder and a subcomponent, and the subcomponent includesterbium (Tb) as a first subcomponent including a lanthanide rare earthelement. The content ratio of the terbium (Tb) to the content of thefirst subcomponent (RE) excluding the terbium (Tb) satisfies0.110≤Tb/RE≤2.333. In one example, the content ratio of the presentdisclosure may refer to a mole ratio.

The first and second side margins 113 and 114 include a barium titanatebase material powder and a subcomponent, and the subcomponent includesterbium (Tb) as a first subcomponent including a lanthanide rare earthelement, and the above problem may be solved by adjusting the contentratio of terbium (Tb) to the content of the first subcomponent (RE)except for the terbium (Tb) to satisfy 0.110≤Tb/RE≤2.333.

In detail, according to an embodiment, a decrease in the interfacialadhesion between the internal electrode and the margin portion may beprevented, and the generation of voids between the internal electrodeand the margin portion may be prevented, thereby improving reliability.

In addition, uniform oxide layer and insulating layer may be secured onthe end of the internal electrode, to reduce short defects, and thedensity of the margin portion may be improved, and the mechanicalstrength of the multilayer ceramic capacitor and the hightemperature/moisture reliability may be improved.

If the content ratio (Tb/RE) of the terbium (Tb) to the content of thefirst subcomponent (RE) excluding the terbium (Tb) is less than 0.110,the content of terbium (Tb) is relatively small and thus, voidsgenerated between the internal electrode and the margin portion may notbe effectively filled, degrading reliability.

If the content ratio (Tb/RE) of the terbium (Tb) to the content of thefirst subcomponent (RE) excluding the terbium (Tb) exceeds 2.333, thecontent of terbium (Tb) is excessive. Thus, there is a side effectaccompanied by a decrease in dielectric layer insulation resistance dueto an increase in leakage current due to the electron emissionphenomenon by the reaction formula.

According to an embodiment, the content of the terbium (Tb) included inthe first and second side margins 113 and 114 may satisfy 0.15mol≤Tb≤1.35 mol with respect to 100 mol of the base material powderincluded in the first and second side margins 113 and 114.

Since the content of the terbium (Tb) included in the first and secondside margins 113 and 114 satisfies 0.15 mol≤Tb≤1.35 mol with respect to100 mol of the base metal powder included in the first and second sidemargins 113 and 114, a decrease in the interface adhesion between theinternal electrode and the margin portion may be prevented and thereliability may be improved by preventing the generation of voidsbetween the internal electrode and the margin.

In addition, the uniform oxide layer and insulating layer may be securedon the end of the internal electrode, to reduce short defects, toimprove the density of the margin portion, and to improve the mechanicalstrength of the multilayer ceramic capacitor and improve the hightemperature/moisture reliability.

If the content of terbium (Tb) is less than 0.15 mol compared to 100 molof the base metal powder, the content of terbium (Tb) may be relativelysmall so that the gap between the internal electrode and the margin maynot be effectively filled and reliability may be deteriorated.

If the content of terbium (Tb) exceeds 1.35 mol relative to 100 mol ofthe base metal powder, the content of terbium (Tb) is excessive, and dueto an increase in leakage current due to electron emission generated bya defect chemical reaction equation, there is a side effect accompaniedby a decrease in dielectric layer insulation resistance.

According to an embodiment of the present disclosure, the subcomponentincludes magnesium (Mg) and barium (Ba), and the content ratio ofmagnesium (Mg) to content of the barium (Ba) may satisfy0.125≤Mg/Ba≤0.500.

The subcomponent includes magnesium (Mg) and barium (Ba), by adjustingthe content ratio of the magnesium (Mg) to the content of the barium(Ba) to satisfy 0.125≤Mg/Ba≤0.500, the interfacial adhesion between theinternal electrode and the margin may be prevented from decreasing, andthe reliability may be improved by preventing the formation of voidsbetween the internal electrode and the margin.

In addition, the uniform oxide layer and insulating layer may be securedon the end of the internal electrode, to reduce short defects, toimprove the density of the margin portion, and to improve the mechanicalstrength of the multilayer ceramic capacitor and improve the hightemperature/moisture reliability.

If the content ratio (Mg/Ba) of the magnesium (Mg) to the content of thebarium (Ba) is less than 0.125, problems such as deterioration of thedensity of margins, generation of interfacial voids, and uneventhicknesses of dielectric and internal electrode ends occur, andreliability may be degraded.

If the content ratio (Mg/Ba) of the magnesium (Mg) to the content of thebarium (Ba) exceeds 0.500, the dielectric properties may decrease.

The content of magnesium (Mg) may satisfy 0.25 mol≤Mg≤1.0 mol comparedto 100 mol of the base material powder.

By adjusting the content of magnesium (Mg) to satisfy 0.25 mol≤Mg≤1.0mol compared to 100 mol of the base material powder, the degradation ofthe interfacial adhesion between the internal electrode and the marginportion may be prevented, the generation of voids between the internalelectrode and the margin portion may be prevented, thereby improving thereliability.

In addition, it is possible to secure uniform oxide layer and insulatinglayer on the end of the internal electrode, to reduce short defects, toimprove the density of the margin portion, and to improve the mechanicalstrength of the multilayer ceramic capacitor and improve the hightemperature/moisture reliability.

If the content of magnesium (Mg) is less than 0.25 mol compared to 100mol of the base metal powder, problems such as deterioration of margindensity, generation of interfacial voids, and nonuniform thicknesses ofthe dielectric and internal electrode ends may occur, thereby reducingthe reliability.

If the content of the magnesium (Mg) exceeds 1.0 mol compared to 100 molof the base metal powder, dielectric properties may decrease.

As described above, the internal electrode is exposed in the widthdirection of the body, thereby significantly increasing the internalelectrode area in the width direction through a margin-free design. Inthis case, in the case of manufacturing a multilayer ceramic capacitorby a method of separately attaching a margin portion to the electrodeexposed surface of the chip in the width direction in the operationbefore firing after the fabrication of the chip, the upper and lowerelectrodes may be connected by the sliding phenomenon of the internalelectrode exposed surface during the cutting process of the internalelectrode exposed surface, which may cause a short circuit and adecrease in withstand voltage.

In addition, physical/chemical phenomena in which an interface is openedmay occur due to a spontaneous reaction to lower surface energy due to areduction in specific surface area during sintering at an interface atthe time of performing heterojunction a metal and a ceramic.

Therefore, to solve both of these problems, it is necessary to select anelement capable of forming a uniform oxide layer without forming asecondary phase, while having high affinity with nickel (Ni) used as aninternal electrode and thus being easily able to be solid dissolved.

According to an embodiment of the present disclosure, with the samestructure as NiO composed of a NaCl structure in which the cation andanion ratio is 1:1, and simultaneously, by controlling the absolutecontent ratio of Mg oxide having a high oxygen affinity, the bondingforce with the side margin ceramic by generation of the oxide layer maybe increased in addition to the even formation of an insulating layer onthe nickel (Ni) electrode end.

In this case, in a case in which the content ratio of Mg exceeds anoptimum composition ratio, the sinterability may be lowered and to belowered due to the excessive Mg addition or the withstand voltage maydecrease due to the generation of the secondary phase. Thus, theselection of the content ratio may be significantly important.

In addition, to further improve the withstand voltage of the multilayerceramic capacitor including moisture resistance and to suppress crackgeneration, the densities of side margins should be secured, and thevoids of electrode ends should be effectively filled. To this end,improving sintering driving force and inducing active mass transport athigh temperatures are required.

The content of the barium (Ba) may satisfy 0.5 mol≤Ba≤3.0 mol withrespect to 100 mol of the base material powder.

Detailed description of the content of the barium (Ba) will be describedlater.

According to an embodiment of the present disclosure, the subcomponentmay include a second subcomponent which is an oxide or carbonatecontaining the Ba, and a third subcomponent with a content greater than0.0 and less than 4.5 mol, including at least one of a carbonate oroxide having at least one of silicon (Si) or aluminum (Al), or glasscompounds containing Si, with respect to 100 mol of the base materialpowder. The content ratio of the magnesium (Mg) relative to the totalcontent of the barium (Ba) and silicon (Si) may satisfy0.09≤Mg/(Ba+Si)≤0.19.

By adjusting the content ratio of the magnesium (Mg) to the totalcontent of the barium (Ba) and silicon (Si) to satisfy0.09≤Mg/(Ba+Si)≤0.19, the formation of voids between the internalelectrode and the margin may be prevented, thereby improvingreliability.

In addition, a uniform oxide layer and an insulating layer may besecured on the end of the internal electrode, to reduce short defects,to improve the density of the margin portion, and to improve themechanical strength of the multilayer ceramic capacitor and improve thehigh temperature/moisture reliability.

If the content ratio (Mg/(Ba+Si)) of the magnesium (Mg) to the totalcontent of the barium (Ba) and silicon (Si) is less than 0.09, problemssuch as deterioration of the density of margins and generation ofinterface voids occur, and reliability may decrease.

If the content ratio (Mg/(Ba+Si)) of magnesium (Mg) to the total contentof barium (Ba) and silicon (Si) exceeds 0.19, the dielectriccharacteristics may be degraded by excessive diffusion of magnesium (Mg)into the active dielectric layer.

In detail, since barium (Ba) and silicon (Si) are important minorcomponents that determine densification at low temperature by liquidphase sintering or the solubility limit in the BaTiO₃ lattice such asterbium (Tb), magnesium (Mg) or the like, based on the eutectic line ofbinary phase diagrams in the two-element system, the interrelationshipof the addition ratio thereof with terbium (Tb) and magnesium (Mg) maybe important.

According to an embodiment of the present disclosure, the dielectriccomposition included in the first and second side margins 113 and 114and the dielectric composition included in the ceramic body 110 aredifferent from each other. The dielectric composition included in thefirst and second side margins 113 and 114 will be described.

a) Base Material Main Component

A dielectric ceramic composition included in the first and second sidemargins 113 and 114 according to an embodiment of the present disclosuremay include a base material main component including barium (Ba) andtitanium (Ti).

According to an embodiment, the base material main component is BaTiO₃or a main component represented by (Ba, Ca) (Ti, Ca) O₃, (Ba, Ca) (Ti,Zr) O₃, Ba (Ti, Zr) O₃, or (Ba, Ca) (Ti, Sn) O₃, in which Ca, Zr, Sn, orthe like is partially dissolved. The base material main component may beincluded in powder form.

b) First Subcomponent

According to an embodiment, terbium (Tb) is included as a firstsubcomponent containing a lanthanide rare earth element, and in additionthereto, the first subcomponent having a content of greater than 0.0 andless than or equal to 4.0 mol, may be included, which is an oxide orcarbonate including at least one of yttrium (Y), dysprosium (Dy),holmium (Ho), erbium (Er), gadolinium (Gd), cerium (Ce), neodymium (Nd),samarium (Sm), lanthanum (La), ytterbium (Yb) and praseodymium (Pr) withrespect to 100 mol of the base metal powder.

The content of the first subcomponent may be provided based on thecontent of at least one of Tb, Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, La, Yb andPr included in the first subcomponent without distinguishing an additionform such as an oxide or a carbonate.

For example, the sum of the contents of at least one or more elementsamong Tb, Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, La, Yb, and Pr included in thefirst subcomponent may be less than or equal to 4.0 mol, to 100 mol ofthe base material main component.

The first subcomponent prevents deterioration of reliability of themultilayer ceramic capacitor to which the dielectric ceramic compositionis applied in one embodiment.

If the content of the first subcomponent exceeds 4.0 mol with respect to100 mol of the base material main component, high temperature withstandvoltage characteristics may be degraded due to pyrochlor (RE₂Ti₂O₇)(where RE is at least one or more elements among Y, Dy, Ho, Er, Gd, Ce,Nd, Sm, La, Yb, and Pr) secondary phase.

c) Second Subcomponent

According to an embodiment of the present disclosure, the dielectricceramic composition may include a second subcomponent including one ormore selected from the group consisting of oxides and carbonates, a Mgelement.

The second subcomponent may be included in an amount of 0.5 mol≤Mg≤3.0mol with respect to 100 mol of the base material powder.

The content of the second subcomponent may be based on the content of Mgelement included in the second subcomponent without distinguishing anaddition form such as an oxide or a carbonate.

When the second subcomponent is included in an amount of 0.5 mol≤Mg≤3.0mol with respect to 100 mol of the base material powder, hightemperature withstand voltage characteristics may be improved.

d) Third Subcomponent

According to an embodiment, the dielectric ceramic composition mayinclude a third subcomponent including at least one of an oxide orcarbonate including at least one of Si, Ba and Al, or a glass compoundincluding Si.

The third subcomponent may be included in an amount of more than 0.0 andless than 4.5 mol with respect to 100 mol of the base material powder.

The content of the third subcomponent may be based on the content of Si,Ba or Al elements included in the third subcomponent withoutdistinguishing an addition form such as glass, oxide, or carbonate.

If the content of the third subcomponent is included in the amount of4.5 mol or more with respect to 100 mol of the base metal powder, theremay be problems such as lowering of sintering property and density,secondary phase generation, and the like.

A multilayer ceramic capacitor according to another embodiment includesa ceramic body including a first surface and a second surface opposingeach other, and a third surface and a fourth surface connecting thefirst and second surfaces to each other, a plurality of internalelectrodes disposed inside the ceramic body, exposed to the first andsecond surfaces, and having an end exposed to the third or fourthsurface, and a first side margin and a second side margin disposed onend portions of the internal electrodes exposed to the first and secondsurfaces, respectively. The first and second side margins include abarium titanate base material powder and a subcomponent, and thesubcomponent includes Terbium (Tb) as one subcomponent including alanthanide rare earth element. In the first and second side margins, thecontent ratio of the terbium (Tb) to the content of the firstsubcomponent (RE) excluding the terbium (Tb) satisfies0.110≤Tb/RE≤2.333. A dielectric composition included in the first andsecond side margins and a dielectric composition included in the ceramicbody are different from each other. The content of the terbium (Tb)included in the first and second side margins is greater than thecontent of terbium (Tb) in the ceramic body. For example, a contentratio of the terbium (Tb) included in the first and second side marginsto a content of the base material powder included in the first andsecond side margins, may be greater than a content ratio of terbium (Tb)included in the ceramic body to a content of a base material powder suchas a barium titanate-based base powder included in the ceramic body.

According to another embodiment, the dielectric composition included inthe first and second side margins 113 and 114 and the dielectriccomposition included in the ceramic body 110 are different from eachother. The first and second side margins 113 and 114 include a bariumtitanate base material powder and a subcomponent, and the subcomponentincludes terbium (Tb) as a first subcomponent including a lanthaniderare earth element, and the content ratio of the terbium (Tb) to thecontent of the first subcomponent (RE) except for the terbium (Tb)satisfies 0.110≤Tb/RE≤2.333, and the content ratio of the terbium (Tb)included in the first and second side margins 113 and 114 is more thanthe content ratio of terbium (Tb) contained in the ceramic body 110.

In the multilayer ceramic capacitor according to another embodiment, thedielectric composition included in the first and second side margins 113and 114 and the dielectric composition included in the ceramic body 110are different from each other. The content ratio of the terbium (Tb)included in the first and second side margins 113 and 114 is adjusted tobe higher than the content ratio of terbium (Tb) included in the ceramicbody 110, thereby to provide an effect according to an embodiment of thepresent disclosure.

In detail, according to another embodiment, the interfacial adhesionbetween the internal electrode and the margin portion may be preventedfrom being lowered, and the formation of voids between the internalelectrode and the margin portion may be prevented, thereby improvingreliability.

In addition, uniform oxide layer and insulating layer may be formed onthe end of the internal electrode, to reduce short defects, to improvethe density of the margin portion, and to improve the mechanicalstrength of the multilayer ceramic capacitor and improve the hightemperature/moisture reliability.

Hereinafter, a method of manufacturing a multilayer ceramic capacitoraccording to another embodiment will be described.

FIGS. 5A to 5F are cross-sectional views and perspective viewsschematically illustrating a method of manufacturing a multilayerceramic capacitor according to another embodiment.

As illustrated in FIG. 5A, a plurality of stripe-type first internalelectrode patterns 221 a are formed on a ceramic green sheet 212 a at apredetermined interval d4. The plurality of stripe-type first internalelectrode patterns 221 a may be formed in parallel to each other.

The predetermined interval d4 is a distance for the internal electrodesto be insulated from the external electrode, having differentpolarities, and may be understood as a distance of d2×2 illustrated inFIG. 4.

The ceramic green sheet 212 a may be formed of a ceramic paste includingceramic powder, an organic solvent, and an organic binder.

The ceramic powder is a material having a high dielectric constant, andalthough not particularly limited, as the ceramic powder, a bariumtitanate (BaTiO₃)-based material, a lead composite perovskite-basedmaterial, a strontium titanate (SrTiO₃)-based material, or the like maybe used, and in detail, barium titanate (BaTiO₃) powder may be used.When the ceramic green sheet 212 a is fired, the ceramic green sheet 212a becomes the dielectric layer 112 constituting the ceramic body.

The stripe-type first internal electrode pattern 221 a may be formed byan internal electrode paste containing a conductive metal. Theconductive metal is not particularly limited, but may be nickel (Ni),copper (Cu), palladium (Pd), or alloys thereof.

The method of forming the stripe-type first internal electrode pattern221 a on the ceramic green sheet 212 a is not particularly limited, butmay be formed by, for example, a printing method such as a screenprinting method or a gravure printing method.

Although not illustrated, a plurality of stripe-type second internalelectrode patterns 222 a (shown in FIG. 5B) may be formed on the otherceramic green sheet 212 a at a predetermined interval.

Hereinafter, the ceramic green sheet on which the first internalelectrode pattern 221 a is formed may be referred to as a first ceramicgreen sheet, and the ceramic green sheet on which the second internalelectrode pattern 222 a is formed may be referred to as a second ceramicgreen sheet.

Next, as illustrated in FIG. 5B, the first and second ceramic greensheets may be alternately stacked so that the stripe-type first internalelectrode patterns 221 a and the stripe-type second internal electrodepatterns 222 a are alternately stacked.

Subsequently, the stripe first internal electrode pattern 221 a may formthe first internal electrode 121, and the stripe second internalelectrode pattern 222 a may form the second internal electrode 122.

FIG. 5C is a cross-sectional view illustrating a ceramic green sheetlaminate 210 in which the first and second ceramic green sheets arestacked according to an embodiment, and FIG. 5D is a perspective view ofthe ceramic green sheet laminate 210 in which the first and secondceramic green sheets are stacked.

Referring to FIGS. 5C and 5D, a first ceramic green sheet on which aplurality of parallel stripe-type first internal electrode patterns 221a are printed, and a second ceramic green sheet on which a plurality ofparallel stripe-type second internal electrode patterns 222 a areprinted are alternately stacked.

In more detail, the green sheets may be stacked in such a manner thatthe center of the stripe-shaped first internal electrode pattern 221 aprinted on the first ceramic green sheet and the interval d4 between thestripe-type second internal electrode patterns 222 a printed on thesecond ceramic green sheet overlap each other.

Next, as illustrated in FIG. 5D, the ceramic green sheet laminate 210may be cut to transverse the plurality of stripe-type first internalelectrode patterns 221 a and the stripe-type second internal electrodepatterns 222 a. For example, the ceramic green sheet laminate 210 may becut into bar laminates 220 along line C1-C1.

In more detail, the stripe-type first internal electrode pattern 221 aand the stripe-type second internal electrode pattern 222 a may be cutin the length direction and divided into a plurality of internalelectrodes having a predetermined width. At this time, the stackedceramic green sheets are also cut together with the internal electrodepatterns. Accordingly, the dielectric layer may be formed to have thesame width as that of the internal electrode.

Ends of the first and second internal electrodes may be exposed to thecut surface of the bar laminate 220. The cut surfaces of the barlaminate may be referred to as first and second sides of the barlaminate, respectively.

The ceramic green sheet laminate may be fired and may then be cut intothe bar laminates. In addition, firing may be performed after theceramic green sheet is cut into the bar laminates. Although notparticularly limited, the firing may be performed in an N₂—H₂ atmosphereof 1100° C. to 1300° C.

Next, as illustrated in FIG. 5E, a first side margin 213 a and a secondside margin 214 a may be formed on the first and second side surfaces ofthe bar laminate 220, respectively. The second side margin 214 a is notclearly illustrated, but is outlined in dotted line.

The first and second side margins 213 a and 214 a may be provided byforming a ceramic slurry including ceramic powder on the bar laminate220.

The ceramic slurry may include a ceramic powder, an organic binder, andan organic solvent, and the amount of the ceramic slurry may be adjustedsuch that the first and second side margins 213 a and 214 a have arequired thickness.

The first and second side margins 213 a and 214 a may be formed byapplying a ceramic slurry to the first and second side surfaces of thebar laminate 220. The method of applying the ceramic slurry is notparticularly limited, and may be applied by spraying or using a roller,for example.

In addition, the bar laminate may be dipped in the ceramic slurry toform the first and second side margins 213 a and 214 a on the first andsecond side surfaces of the bar laminate.

As described above, the thicknesses of the first and second side marginsmay be 18 μm or less.

Next, as illustrated in FIGS. 5E and 5F, the bar laminate 220 having thefirst and second side margins 113 a and 114 a formed thereon may be cutinto individual chips with respectively required sizes, along a C2-C2cutting line. FIG. 5C may be referred to determine the position of theC2-C2 cutting line.

As the bar laminate 220 is cut into chip size, a ceramic body having alaminated body 111 and the first and second side margins 113 and 114formed on both sides of the laminated body may be formed.

As the bar laminate 220 is cut along the C2-C2 cutting line, a centerportion of the overlapped first and second internal electrodes, and thepredetermined interval d4 between the second internal electrodes, may becut by the same cutting line. From another point of view, a centralportion of the second internal electrode, and a predetermined intervalbetween the first internal electrodes, may be cut by the same cuttingline.

Accordingly, one ends of the first internal electrode and the secondinternal electrode may be alternately exposed to the cutting surfacealong the C2-C2 cutting line. The surface to which the first internalelectrode is exposed may be understood to be the third surface 3 of thelaminate illustrated in FIG. 4, and the surface to which the secondinternal electrode is exposed may be understood to be the fourth surface4 of the laminate illustrated in FIG. 4.

As the bar laminate 220 is cut along the C2-C2 cutting line, thepredetermined interval d4 between the sprite-type first internalelectrode patterns 221 a is cut in half, such that one end of the firstinternal electrode 121 is spaced apart from the fourth surface by apredetermined interval d2. In addition, one end of the second internalelectrode 122 is allowed to be spaced apart from the third surface by apredetermined interval d2.

Thereafter, an external electrode may be formed on each of the third andfourth surfaces to be connected to one ends of the first and secondinternal electrodes.

As in this embodiment, when the first and second side margins are formedon the bar laminate 220 and cut into chip sizes, the side margins may beformed on a plurality of laminated bodies 111 through one process.

In addition, although not illustrated, a plurality of laminates may beformed by cutting the bar laminate into chip sizes before forming thefirst side margin and the second side margin.

For example, the bar laminate may be cut, such that the central portionof the overlapping first internal electrode, and a predeterminedinterval between the second internal electrodes, are cut by the samecutting line. Accordingly, one ends of the first internal electrode andthe second internal electrode may be alternately exposed to the cutsurface.

Thereafter, the first side margin and the second side margin, made ofthe above described material, may be formed on the first and secondsurfaces of the laminated body. A method of forming the first and secondside margins is as described above.

In addition, an external electrode may be formed on a third surface ofthe laminated body to which the first internal electrode is exposed andanother external electrode may be formed on a fourth surface of thelaminated body to which the second internal electrode is exposed.

According to another embodiment, the ends of the first and secondinternal electrodes are exposed through the first and second surfaces ofthe laminate. The plurality of stacked first and second internalelectrodes may be simultaneously cut, and thus, the ends of the internalelectrodes may be disposed on one straight line. Thereafter, first andsecond side margins are collectively formed on the first and secondsurfaces of the laminate. The ceramic body is formed by the laminate andthe first and second side margins. For example, the first and secondside margins form on the first and second side surfaces of the ceramicbody, respectively.

Accordingly, according to this embodiment, the distance from the ends ofthe plurality of internal electrodes to the first and second surfaces ofthe ceramic body may be uniformly formed. In addition, the first andsecond side margins are formed by a ceramic paste, and may have arelatively thin thickness.

Hereinafter, an embodiment of the present disclosure will be describedin more detail with reference to an experimental example. However, thescope of the present disclosure is not limited by the experimentalexample.

Experimental Example

As a base material main component, a BaTiO₃ powder of 100 nm or less wasused, and a subcomponent composition in this case is illustrated inTable 1 below.

In preparing a slurry, the base material main component and subcomponentpowder were mixed with ethanol/toluene and a dispersant by usingzirconia balls as mixing/dispersing media, and then, mechanical millingwas performed, and then a binder mixing process for implementingdielectric sheet strength was added.

The prepared slurry was manufactured into a sheet having a thickness of10 to 20 μm to form a side margin using an on-roll coater of the headdischarge method.

In addition, the sheet was attached to an electrode exposed portion ofthe green chip in which the internal electrode is exposed in the widthdirection and there is no margin, and was cut to have a size of 5 cm×5cm to form the side margin.

A multilayer ceramic capacitor green chip of 0603 size(width×length×height: 0.6 mm×0.3 mm×0.3 mm) was fabricated by attachingthe sheet to both sides of the chip by applying a constant temperatureand pressure under the condition of significantly reducing chipdeformation.

The fabricated multilayer ceramic capacitor specimen was subjected to aplasticizing process under nitrogen atmosphere at 400° C. or lower, andthen subjected to firing under the conditions of firing temperature of1200° C. or lower and hydrogen concentration of 0.5% H₂ or less. Then,electrical characteristics, insulation resistance, chip strength, theadhesion at the interface between the side margin and internal electrodeand void filling therebetween, the degree of formation of insulationlayer on the electrode end, the difference in the density of the sidemargins and the like were comprehensively confirmed.

Dielectric loss and the room temperature capacitance of the multilayerceramic capacitor (MLCC) for each composition were measured at 1 kHz andAC 0.5 V, using an LCR meter, and 50 samples were taken to measure abreakdown voltage (BDV), which causes breakdown.

Side margin hardness of the multilayer ceramic capacitor (MLCC) wasmeasured using a Vickers hardness tester under 5 kgf load and holdingtime of 5 sec. The microstructures such as a margin density and aninsulation layer generation degree were compared for a fracture surfaceand a polishing surface of the chip.

Table 1 below is a dielectric composition table of Experimental Example(Comparative Examples and Embodiment Examples), and BaTiO₃ is used as abase material main component. In this case, as the subcomponent, anadditional element in the form of a basic donor and acceptorconstituting the multilayer ceramic capacitor (MLCC), and elementsserving as a sintering aid including Ba—Si—Al were used.

At this time, to compare the densities of the side margins, theformation of an oxide layer on an electrode end, the void filling, andthe interfacial adhesion according to Embodiment Examples of the presentinvention and Comparative Examples, the additive element content ratioswere variously changed for respective subcomponents.

Table 2 below summarizes the electrical characteristics andmicrostructure results of the 0603 size multilayer ceramic capacitor(MLCC) corresponding to the composition specified in Table 1 above.

TABLE 1 Mole number of additive per 100 mol of BatiO3 base materialFirst Subcomponent Second Third total Tb in total RE in SubcomponentSubcomponent Main Subcomponent Ratio Sample Tb₄O₇ RE₂O₃ MgCO₃ BaCO₃ SiO₂Tb/RE Mg/Ba Mg/(Ba + Si) *1 0.00 1.50 0.50 2.0 3.3 — 0.250 0.094 2 0.151.35 0.50 2.0 3.3 0.111 0.250 0.094 3 0.30 1.20 0.50 2.0 3.3 0.250 0.2500.094 4 0.45 1.05 0.50 2.0 3.3 0.429 0.250 0.094 5 0.60 0.90 0.50 2.03.3 0.667 0.250 0.094 6 0.75 0.75 0.50 2.0 3.3 1.000 0.250 0.094 7 0.900.60 0.50 2.0 3.3 1.500 0.250 0.094 8 1.05 0.45 0.50 2.0 3.3 2.333 0.2500.094 *9 1.20 0.30 0.50 2.0 3.3 4.000 0.250 0.094 *10 1.35 0.15 0.50 2.03.3 9.000 0.250 0.094 *11 1.50 0.00 0.50 2.0 3.3 — 0.250 0.094 *12 0.451.05 0.0 2.0 3.3 0.429 0.000 0.000 *13 0.45 1.05 0.25 2.0 3.3 0.4290.125 0.047 14 0.45 1.05 0.75 2.0 3.3 0.429 0.375 0.142 15 0.45 1.051.00 2.0 3.3 0.429 0.500 0.189 *16 0.45 1.05 0.75 0.5 3.3 0.429 1.5000.197 *17 0.45 1.05 0.75 1.0 3.3 0.429 0.750 0.174 18 0.45 1.05 0.75 1.53.3 0.429 0.500 0.156 19 0.45 1.05 0.75 2.5 3.3 0.429 0.300 0.129 200.45 1.05 0.75 3.0 3.3 0.429 0.250 0.119 *21 0.45 1.05 0.75 2.5 1.50.429 0.300 0.191 *22 0.45 1.05 0.75 2.5 4.5 0.429 0.300 0.107

TABLE 2 Structural Characteristics Electrical Characteristics Depth ofHigh Oxide Layer Interfacial Body Smoothness Dielectric and temperatureMoisture on Electrode void filling Density Interfacial Strength ofElectrode thickness Dielectric withstand resistance Short Sample Endsrate of Margin Adhesion of Margin End uniformity constant voltagereliability Rate *1 Δ X X X X X X ◯ X X X 2 Δ ◯ Δ ◯ Δ Δ Δ ◯ Δ Δ Δ 3 Δ Δ◯ Δ ◯ ◯ ◯ ◯ ◯ ◯ ◯ 4 Δ ◯ ⊚ ◯ ⊚ ◯ ◯ ◯ ◯ ⊚ ◯ 5 Δ ◯ ⊚ ◯ ⊚ ◯ ◯ ◯ Δ ◯ ◯ 6 Δ ◯◯ ◯ ◯ ◯ ◯ ◯ Δ Δ ◯ 7 Δ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ 8 Δ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ 9 Δ ◯◯ ◯ ◯ Δ Δ ◯ X X X *10 Δ Δ Δ Δ Δ X X ◯ X X X *11 Δ X X X X X X ◯ X X X*12 X X Δ Δ Δ X X ⊚ X X X *13 X Δ Δ Δ Δ X X ⊚ ◯ ◯ Δ 14 ⊚ ⊚ ⊚ ⊚ ⊚ ◯ ◯ ◯ ⊚⊚ ⊚ 15 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Δ ◯ ◯ ⊚ *16 ⊚ Δ Δ Δ Δ X X Δ X X X *17 ⊚ Δ ◯ Δ Δ Δ ΔΔ Δ X Δ 18 ⊚ ◯ ⊚ ◯  © ◯ ◯ ◯ Δ ◯ ◯ 19 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ 20 ⊚ ◯ ◯ ◯ ◯◯ ◯ ◯ ◯ ◯ ⊚ *21 ⊚ Δ Δ Δ Δ X X Δ X X X *22 ⊚ ⊚ Δ ◯ Δ Δ Δ Δ Δ Δ X ⊚:Excellent, ◯: Good, Δ: Normal, X: Poor

As illustrated in Table 1 and Table 2, when the ratio of terbium (Tb) inthe rare earth element increases to a certain level or more, theinterface void filling effect may be obtained by improving the bodydensity and body strength and improving the material transfer drivingforce of the body. The content ratio of the terbium (Tb) to the contentof the first subcomponent (RE), excluding the terbium (Tb), may be up to9.0.

However, in consideration of the high temperature and moistureresistance reliability of the multilayer ceramic capacitor, in case ofterbium (Tb) having a strong donor type tendency, in the case in whichthe content ratio is excessively high, leakage current increases due tothe electron emission phenomenon generated by a defect chemical reactionequation. Since a side effect accompanied by a decrease in dielectriclayer insulation resistance occurs, the content ratio of the terbium(Tb) to the content of the first subcomponent (RE) excluding the terbium(Tb) may satisfy 0.110≤Tb/RE≤2.333, to simultaneously obtain the effectsof densification of the body and the increase of insulation resistanceof the dielectric layer.

In addition, the content ratio of the magnesium (Mg) to the content ofthe barium (Ba) may satisfy 0.125≤Mg/Ba≤0.500.

By adjusting the content ratio of the magnesium (Mg) to the content ofthe barium (Ba) to satisfy 0.125≤Mg/Ba≤0.500, the degradation of theinterfacial adhesion between the internal electrode and the margin maybe prevented, and the generation of voids between the internal electrodeand the margin may be prevented, thereby improving the reliability.

In addition, a uniform oxide layer and insulating layer on the end ofthe internal electrode may be secured, to reduce short defects, toimprove the density of the margin portion, and to improve the mechanicalstrength of the multilayer ceramic capacitor and improve the hightemperature/moisture resistance reliability.

In the case of samples 12, 16 and 17, the content ratio of magnesium(Mg) to the content of barium (Ba) is outside the numerical rangeaccording to an embodiment of the present disclosure. In this case, themargin density decreases, the interfacial voids occur, and the thicknessuniformity on the dielectric and internal electrode ends may be lowered.Further, a decrease in dielectric properties may occur.

On the other hand, the content ratio of magnesium (Mg) to the totalcontent of barium (Ba) and silicon (Si) may satisfy0.09≤Mg/(Ba+Si)≤0.19.

In an embodiment in which the content ratio of magnesium (Mg) to thetotal content of the barium (Ba) and silicon (Si) satisfies0.09≤Mg/(Ba+Si)≤0.19, void generation between the internal electrode andthe margin portion may be prevented, and thus, it can be seen that thereliability may be improved.

In addition, the uniform oxide layer and insulating layer on the end ofthe internal electrode may be secured, to reduce short defects, toimprove the density of the margin portion, and to improve the mechanicalstrength of the multilayer ceramic capacitor. Therefore, it can be seenthat the high temperature/moisture resistance reliability may beimproved.

In the case of Sample 13 in which the content ratio (Mg/(Ba+Si)) ofmagnesium (Mg) to the total content of barium (Ba) and silicon (Si) isless than 0.09, there is a problem in which the margin densitydecreases, the interfacial voids are generated, and the thicknessuniformity on the internal electrode end decreases, thereby causing adecrease in reliability.

In the case of Sample 21 in which the content ratio (Mg/(Ba+Si)) ofmagnesium (Mg) to the total content of barium (Ba) and silicon (Si)exceeds 0.19, excessive diffusion of magnesium (Mg) into the activedielectric layer degrades dielectric properties.

In the case of sample 22, the content of silicon (Si) is out of thenumerical range according to an embodiment of the present disclosure,which may cause problems of degrading sintering properties and density,and short generation.

As set forth above, according to an embodiment, after fabricating thechip in such a manner that the internal electrode is exposed in thewidth direction of the body, a decrease in the interfacial adhesionbetween the internal electrodes and the margins, occurring during themultilayer ceramic capacitor manufacturing process in which the marginsare separately attached to the electrode exposed surface of the chip inthe width direction, in operation before firing, may be prevented.

In addition, in the multilayer ceramic capacitor manufactured by theabove manufacturing process, the generation of voids between theinternal electrode and the margin portion may be prevented, therebyimproving the reliability.

In addition, uniform oxide layer and insulating layer may be secured onthe end of the internal electrode, thereby reducing short defects.

In addition, the density of the margin portion may be improved, therebyimproving the mechanical strength of the multilayer ceramic capacitorand improving the high temperature/moisture resistance.

The internal electrode is formed entirely in the width direction of thedielectric layer, and is exposed to the side of the body in the widthdirection, and then, the margins are attached separately, therebysignificantly increasing the overlapping area between the internalelectrodes to implement a high capacity multilayer ceramic capacitor,and reducing the occurrence of step difference.

While this disclosure includes specific examples, it will be apparent toone of ordinary skill in the art that various changes in form anddetails may be made in these examples without departing from the spiritand scope of the claims and their equivalents. The examples describedherein are to be considered in a descriptive sense only, and not forpurposes of limitation. Descriptions of features or aspects in eachexample are to be considered as being applicable to similar features oraspects in other examples. Suitable results may be achieved if thedescribed techniques are performed to have a different order, and/or ifcomponents in a described system, architecture, device, or circuit arecombined in a different manner, and/or replaced or supplemented by othercomponents or their equivalents. Therefore, the scope of the disclosureis defined not by the detailed description, but by the claims and theirequivalents, and all variations within the scope of the claims and theirequivalents are to be construed as being included in the disclosure.

What is claimed is:
 1. A multilayer ceramic capacitor comprising: aceramic body including first and second surfaces opposing each other,and third and fourth surfaces connecting the first and second surfaces;a plurality of internal electrodes disposed inside the ceramic body,exposed from the first and second surfaces, and having an end exposedfrom the third surface or the fourth surface; and a first side marginand a second side margin respectively disposed on the first and secondsurfaces, from which end portions of the plurality of internalelectrodes are exposed, wherein the first and second side marginsinclude a barium titanate-based base material, and a subcomponent,wherein the subcomponent includes terbium (Tb) as a first subcomponentincluding a lanthanide rare earth element, and a content ratio of theterbium (Tb) to a content of the first subcomponent (RE) excluding theterbium (Tb) satisfies 0.110≤Tb/RE≤2.333 wherein the subcomponentfurther comprises: magnesium (Mg) and barium (Ba); a second subcomponentincluding a carbonate or an oxide comprising magnesium (Mg); and a thirdsubcomponent having a content greater than 0.0 and less than 4.5 molcontaining at least one of an oxide or carbonate comprising at least oneof silicon (Si), barium (Ba) or aluminum (Al), or a glass compoundcomprising Si, with respect to 100 mol of the barium titanate-based basematerial, and wherein a content ratio of the magnesium (Mg) to the totalcontent of the barium (Ba) and silicon (Si) satisfies0.09≤Mg/(Ba+Si)≤0.19.
 2. The multilayer ceramic capacitor of claim 1,wherein a content of the terbium (Tb) satisfies 0.15 mol≤Tb≤1.35 molwith respect to 100 mol of the barium titanate-based base material. 3.The multilayer ceramic capacitor of claim 1, wherein a content ratio ofmagnesium (Mg) to a content of barium (Ba) of the subcomponent satisfies0.125≤Mg/Ba≤0.500.
 4. The multilayer ceramic capacitor of claim 1,wherein the content of magnesium (Mg) satisfies 0.25 mol≤Mg≤1.0 mol withrespect to 100 mol of the barium titanate-based base material.
 5. Themultilayer ceramic capacitor of claim 1, wherein the content of barium(Ba) of the subcomponent satisfies 0.5 mol≤Ba≤3.0 mol with respect to100 mol of the barium titanate-based base material.
 6. The multilayerceramic capacitor of claim 1, wherein the subcomponent comprises thefirst subcomponent in an amount greater than 0.0 and 4.0 mol or lesswith respect to 100 mol of the barium titanate-based base materialpowder, the first subcomponent being an oxide or carbonate including atleast one of yttrium (Y), dysprosium (Dy), holmium (Ho), erbium (Er),gadolinium (Gd), cerium (Ce), neodymium (Nd), samarium (Sm), lanthanum(La), ytterbium (Yb) or praseodymium (Pr).
 7. The multilayer ceramiccapacitor of claim 1, wherein a dielectric composition included in thefirst and second side margins and a dielectric composition included inthe ceramic body are different.
 8. A multilayer ceramic capacitorcomprising: a ceramic body including first and second surfaces opposingeach other, and third and fourth surfaces connecting the first andsecond surfaces; a plurality of internal electrodes disposed inside theceramic body, exposed from the first and second surfaces, and eachhaving an end exposed from the third surface or the fourth surface; anda first side margin and a second side margin respectively disposed onthe first and second surfaces, from which end portions of the pluralityof internal electrodes are exposed, wherein the first and second sidemargins include a barium titanate-based base material, and asubcomponent, wherein the subcomponent includes terbium (Tb) as a firstsubcomponent including a lanthanide rare earth element, wherein acontent ratio of the terbium (Tb) to a content of the first subcomponent(RE) excluding the terbium (Tb) satisfies 0.110≤Tb/RE≤2.333, and whereina content ratio of the terbium (Tb) included in the first and secondside margins to a content of the barium titanate-based base materialincluded in the first and second side margins, is greater than a contentratio of terbium (Tb) included in the ceramic body to a content of abarium titanate-based base material included in the ceramic body.
 9. Themultilayer ceramic capacitor of claim 8, wherein the content of terbium(Tb) included in the first and second side margin satisfies 0.15 mol≤Tb≤1.35 mol with respect to 100 mol of the barium titanate-based basematerial included in the first and second side margins.
 10. Themultilayer ceramic capacitor of claim 8, wherein the subcomponentfurther comprises magnesium (Mg) and barium (Ba), and a content ratio ofmagnesium (Mg) to a content of barium (Ba) in the subcomponent satisfies0.125≤Mg/Ba≤0.500.
 11. The multilayer ceramic capacitor of claim 10,wherein the content of magnesium (Mg) satisfies 0.25 mol≤Mg≤1.0 mol withrespect to 100 mol of the barium titanate-based base material includedin the first and second side margins.
 12. The multilayer ceramiccapacitor of claim 10, wherein the content of barium (Ba) satisfies 0.5mol≤Ba≤3.0 mol with respect to 100 mol of the barium titanate-based basematerial included in the first and second side margins.
 13. Themultilayer ceramic capacitor of claim 10, wherein the subcomponentfurther comprises: a second subcomponent including an oxide or carbonatecomprising the Mg; and a third subcomponent having a content greaterthan 0.0 and less than 4.5 mol containing at least one of an oxide orcarbonate comprising at least one of silicon (Si), barium (Ba) oraluminum (Al), or a glass compound comprising Si, with respect to 100mol of the barium titanate-based base material included in the first andsecond side margins, wherein a content ratio of the magnesium (Mg) to atotal content of the barium (Ba) and silicon (Si) satisfies0.09≤Mg/(Ba+Si)≤0.19.
 14. The multilayer ceramic capacitor of claim 8,wherein the subcomponent comprises the first subcomponent in an amountgreater than 0.0 and 4.0 mol or less with respect to 100 mol of thebarium titanate-based base material included in the first and secondside margins, the first subcomponent being an oxide or carbonateincluding at least one of Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, La, Yb or Pr.15. A multilayer ceramic capacitor comprising: a ceramic body includingfirst and second surfaces opposing each other, and third and fourthsurfaces connecting the first and second surfaces; a plurality ofinternal electrodes disposed inside the ceramic body, exposed from thefirst and second surfaces, and each having an end exposed from the thirdsurface or the fourth surface; and a first side margin and a second sidemargin respectively disposed on the first and second surfaces, fromwhich end portions of the plurality of internal electrodes are exposed,wherein the first and second side margins include a bariumtitanate-based base material and a subcomponent, wherein thesubcomponent includes terbium (Tb) and one or more other lanthanide rareearth elements as a first subcomponent, wherein a content ratio of theterbium (Tb) included in the first and second side margins to a contentof the barium titanate-based base material included in the first andsecond side margins, is greater than a content ratio of terbium (Tb)included in the ceramic body to a content of a barium titanate-basedbase material included in the ceramic body, and wherein a content of theterbium (Tb) satisfies 0.15 mol≤Tb≤1.35 mol with respect to 100 mol ofthe barium titanate-based base material included in the first and secondside margins.
 16. The multilayer ceramic capacitor of claim 15, whereinthe subcomponent further comprises magnesium (Mg) and barium (Ba), and acontent ratio of magnesium (Mg) to a content of barium (Ba) in thesubcomponent satisfies 0.125≤Mg/Ba≤0.500.
 17. The multilayer ceramiccapacitor of claim 16, wherein the content of magnesium (Mg) satisfies0.25 mol≤Mg≤1.0 mol with respect to 100 mol of the barium titanate-basedbase material included in the first and second side margins.
 18. Themultilayer ceramic capacitor of claim 16, wherein the content of barium(Ba) satisfies 0.5 mol≤Ba≤3.0 mol with respect to 100 mol of the bariumtitanate-based base material included in the first and second sidemargins.
 19. The multilayer ceramic capacitor of claim 16, wherein thesubcomponent further comprises: a second subcomponent including an oxideor carbonate comprising the Mg; and a third subcomponent having acontent greater than 0.0 and less than 4.5 mol containing at least oneof an oxide or carbonate comprising at least one of silicon (Si), barium(Ba) or aluminum (Al), or a glass compound comprising Si, with respectto 100 mol of the barium titanate-based base material included in thefirst and second side margins, wherein a content ratio of the magnesium(Mg) to a total content of the barium (Ba) and silicon (Si) satisfies0.09≤Mg/(Ba+Si)≤0.19.
 20. The multilayer ceramic capacitor of claim 15,wherein the subcomponent comprises the first subcomponent in an amountgreater than 0.0 and 4.0 mol or less with respect to 100 mol of thebarium titanate-based base material included in the first and secondside margins, the first subcomponent being an oxide or carbonateincluding at least one of Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, La, Yb or Pr.